Oled display substrate and method of fabricating the same, display panel containing display substrate, and display device containing display panel

ABSTRACT

The present disclosure generally relates to display technologies. A display substrate includes a first base substrate including a plurality of pixel units arranged in an array, at least one of the plurality of pixel units including at least two sub-pixel units and a transparent area. The at least two sub-pixel units includes a first sub-pixel unit that is arranged between transparent areas of adjacent pixel units in a first direction. An orthographic projection of a pixel drive circuit electrically coupled to the first sub-electrode corresponding to the first sub-pixel unit on the first base substrate partially overlaps with an orthographic projection of a first sub-electrode positionally corresponding to another sub-pixel unit on the first base substrate.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation application of U.S. application Ser. No.16/769,353 filed on Jun. 3, 2020, which claims benefit of the filingdate of Chinese Patent Application No. 201910085413.7 filed on Jan. 29,2019, the disclosure of which is hereby incorporated in its entirety byreference.

TECHNICAL FIELD

The present disclosure generally relates to display technologies, and inparticular, to an organic light-emitting diode (OLED) display substrateand a method of fabricating the display substrate, a display panelcontaining the display substrate, and a display device containing thedisplay panel.

BACKGROUND

Display technologies are becoming increasingly diverse, and displaydevices embodying new display technologies are regularly beingintroduced into the market and people's daily lives. Currently, thedisplay technologies mainly include two main categories: organiclight-emitting diode (OLED) technology and liquid crystal display (LCD)technology. The field of LCD technology is established and mature, andrecent developments trend toward providing ultra-high resolution. Thefield of OLED technology is still maturing. OLED technology is commonlyused in mobile phones, tablets, and other display devices having smallto medium-sized screens. Of course, OLED technology is also used inlarge-screen televisions.

BRIEF SUMMARY

An embodiment of the present disclosure is a display substrate. Thedisplay substrate may comprise a first base substrate comprising aplurality of pixel units arranged in an array, at least one of theplurality of pixel units comprising at least two sub-pixel units and atransparent area; a first electrode layer on the first base substratecomprising a plurality of first sub-electrodes, each of the plurality offirst sub-electrodes positionally corresponding to one of the at leasttwo sub-pixel units; a pixel define layer on the first electrode layer,the pixel define layer comprising a plurality of openings, each of theplurality of openings positionally corresponding to a light-emittingregion of one of the at least two sub-pixel units and to the transparentarea; and a plurality of pixel drive circuits, each of the plurality ofpixel drive circuits being electrically coupled to a corresponding oneof the plurality of first sub-electrodes. The at least two sub-pixelunits may comprise a first sub-pixel unit, the first sub-pixel unitbeing arranged between transparent areas of adjacent pixel units in afirst direction. An orthographic projection of a pixel drive circuitelectrically coupled to the first sub-electrode corresponding to thefirst sub-pixel unit on the first base substrate may partially overlapwith an orthographic projection of a first sub-electrode positionallycorresponding to another sub-pixel unit on the first base substrate.

In at least some embodiments, the orthographic projection on the firstbase substrate of the pixel drive circuit electrically coupled to thefirst sub-electrode corresponding to the first sub-pixel unit maypartially overlap with an orthographic projection on the first basesubstrate of a first sub-electrode positionally corresponding to asub-pixel unit nearest to the first sub-pixel unit.

In at least some embodiments, the display substrate may further comprisea plurality of signal wires extending in a second direction. In at leastsome embodiments, the second direction may intersect with the firstdirection.

In at least some embodiments, an orthographic projection of alight-emitting region of the first sub-pixel unit on the first basesubstrate may be within an orthographic projection of the plurality ofsignal wires on the first base substrate.

In at least some embodiments, the first sub-pixel unit may have arectangular shape, and a ratio of a length of the first sub-pixel unitto a width of the first sub-pixel unit may be from 9:1 to 5:1.

In at least some embodiments, the first sub-pixel unit may be configuredto emit a white light.

In at least some embodiments, the display substrate may further comprisea light-emitting layer on the first electrode layer, and a secondelectrode layer on the light-emitting layer.

In at least some embodiments, the display substrate may further comprisea first auxiliary electrode layer on the second electrode layer. In atleast some embodiments, the first auxiliary electrode layer may beelectrically coupled to the second electrode layer.

In at least some embodiments, the display substrate may further comprisea first black matrix on the second electrode layer. In at least someembodiments, an orthographic projection of the first black matrix on thefirst base substrate may be within an orthographic projection of thepixel define layer.

In at least some embodiments, the display substrate may further comprisea first color filter layer on a side of the first black matrix oppositefrom the first base substrate. In at least some embodiments, the firstcolor filter layer may be arranged to positionally correspond to any oneof the at least two sub-pixel units other than the first sub-pixel unitand to the transparent area.

In at least some embodiments, each pixel drive circuit may comprise acapacitor, a first thin film transistor, and a second thin filmtransistor. In at least some embodiments, the capacitor may comprise afirst capacitor layer and a second capacitor layer. In at least someembodiments, the first thin film transistor may comprise a first activelayer, a first gate electrode, a first source electrode, and a firstdrain electrode. In at least some embodiments, the second thin filmtransistor may comprise a second active layer, a second gate electrode,a second source electrode, and a second drain electrode. In at leastsome embodiments, the first capacitor layer may be electrically coupledto the first gate electrode, and one of the second source electrode andthe second drain electrode. In at least some embodiments, the secondcapacitor layer may be electrically coupled to one of the first sourceelectrode and the first drain electrode, and one of the plurality ofelectrode corresponding to the pixel drive circuit.

In at least some embodiments, the second capacitor layer may be providedin a same layer as the first active layer.

In at least some embodiments, the first capacitor layer may be providedin a same layer as the first electrode layer.

In at least some embodiments, the first electrode layer may comprise areflective electrode layer and a transparent electrode layer arranged inthis order in a direction away from the first base substrate.

In at least some embodiments, the first capacitor layer may be providedin a same layer as the transparent electrode layer.

In at least some embodiments, the first capacitor layer may be providedin a same layer as one of the first source electrode and the first drainelectrode.

Another embodiment of the present disclosure is a display device. Thedisplay device may comprise a display substrate as described above, andan opposite substrate comprising a second base substrate and a secondblack matrix on the second base substrate.

In at least some embodiments, an orthographic projection of the secondblack matrix on the first base substrate may be within an orthographicprojection of the pixel define layer on the first base substrate.

In at least some embodiments, the display device may further comprise asecond color filter layer on a side of the second black matrix oppositefrom the second base substrate. In at least some embodiments, the secondcolor filter layer may be arranged to positionally correspond to any oneof the at least two sub-pixel units other than the first sub-pixel unitand to the transparent area.

In at least some embodiments, the display device may further comprise asecond auxiliary electrode layer on a side of the second color filterlayer opposite from the second base substrate. In at least someembodiments, the second auxiliary electrode layer may be configured tobe electrically coupled to the second electrode layer. In at least someembodiments, the second auxiliary electrode layer may be composed of ametal material. In at least some embodiments, the second electrode layermay be composed of a transparent material.

Another embodiment of the present disclosure is a method of fabricatinga display substrate. The method may comprise forming a first basesubstrate comprising a plurality of pixel units arranged in an array, atleast one of the plurality of pixel units comprising at least twosub-pixel units and a transparent area; forming a first electrode layeron the first base substrate, the first electrode layer comprising aplurality of first sub-electrodes, each of the plurality of firstsub-electrodes positionally corresponding to one of the at least twosub-pixel units; forming a pixel define layer on the first electrodelayer, the pixel define layer comprising a plurality of openings, eachof the plurality of openings positionally corresponding to alight-emitting region of one of the at least two sub-pixel units and tothe transparent area; and forming a plurality of pixel drive circuits,each of the plurality of pixel drive circuits being electrically coupledto a corresponding one of the plurality of first sub-electrodes.

In at least some embodiments, the at least two sub-pixels may comprise afirst sub-pixel unit, the first sub-pixel unit being arranged betweentransparent areas of adjacent pixel units in a first direction.

In at least some embodiments, an orthographic projection of a pixeldrive circuit electrically coupled to the first sub-electrodecorresponding to the first sub-pixel unit on the first base substratemay partially overlap with an orthographic projection of a firstsub-electrode positionally corresponding to another one of the at leasttwo sub-pixel units on the first base substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter that is regarded as the invention is particularlypointed out and distinctly claimed in the claims at the conclusion ofthe specification. The foregoing and other objects, features, andadvantages of the present disclosure are apparent from the followingdetailed description taken in conjunction with the accompanying drawingsin which:

FIG. 1 shows a schematic diagram of a top view of an OLED displaysubstrate according to an embodiment of the present disclosure;

FIG. 2 shows a schematic diagram of a cross-sectional view of the OLEDdisplay substrate illustrated in FIG. 1 along the A-A′ line;

FIG. 3 shows a schematic diagram of a cross-sectional view of an OLEDdisplay substrate according to an embodiment of the present disclosure;

FIG. 4 shows a circuit diagram for a pixel drive circuit according to anembodiment of the present disclosure;

FIG. 5 shows a schematic diagram of a top view of a pixel drive circuitcorresponding to a sub-electrode in an OLED display substrate accordingto an embodiment of the present disclosure;

FIG. 6 shows a schematic diagram of a cross-sectional of an OLED displaysubstrate according to another embodiment of the present disclosure;

FIG. 7 shows a schematic diagram of a display panel according to anembodiment of the present disclosure;

FIG. 8 shows a schematic diagram of a front plate for a display panelaccording to an embodiment of the present disclosure; and

FIG. 9 shows a flow chart for a method of fabricating an OLED displaysubstrate according to an embodiment of the present disclosure.

The various features of the drawings are not to scale as theillustrations are for clarity in facilitating one skilled in the art inunderstanding the invention in conjunction with the detaileddescription.

DETAILED DESCRIPTION

Next, the embodiments of the present disclosure will be describedclearly and concretely in conjunction with the accompanying drawings,which are described briefly above. The subject matter of the presentdisclosure is described with specificity to meet statutory requirements.However, the description itself is not intended to limit the scope ofthis disclosure. Rather, the inventors contemplate that the claimedsubject matter might also be embodied in other ways, to includedifferent steps or elements similar to the ones described in thisdocument, in conjunction with other present or future technologies.

While the present technology has been described in connection with theembodiments of the various figures, it is to be understood that othersimilar embodiments may be used or modifications and additions may bemade to the described embodiments for performing the same function ofthe present technology without deviating therefrom. Therefore, thepresent technology should not be limited to any single embodiment, butrather should be construed in breadth and scope in accordance with theappended claims. In addition, all other embodiments obtained by one ofordinary skill in the art based on embodiments described in thisdocument are considered to be within the scope of this disclosure.

Currently, the display technologies mainly include two main categories:organic light-emitting diode (OLED) technology and liquid crystaldisplay (LCD) technology. OLED is an organic thin filmelectroluminescent display device, and has numerous advantages thatcontribute to their popularity in the field of display technology. Forexample, OLED devices are self-illuminating, and are capable of highluminance, high contrast, simple construction, low power consumption andhigh energy efficiency, wide viewing angles, flexible display, andthree-dimensional (3D) display. These advantages combine to make OLED afocus in the developments of display technologies.

Further, continuous revamping and advancements in display technologieshave produced a new form of display device: a transparent displaydevice. When a transparent display device is not in use, the user cansee through the display device. This transparency is the commercialappeal of the transparent display devices that makes them the focus ofrecent developments in display technologies.

The display panels on transparent display devices commonly incorporateOLED technology. The transparent display panels generally include aplurality of pixel units. Each pixel unit may in turn include atransparent area and at least two color sub-pixel units. The at leasttwo color sub-pixel units may include, for example, a red sub-pixelunit, a green sub-pixel unit, and a blue sub-pixel unit.

A transparent display panel commonly includes signal wires fortransmitting display drive signals. To prevent the signal wires fromreflecting ambient light incident on the transparent display panel, thesignal wires are often covered with a black matrix. The black matrix,however, tends to occupy a portion of the pixel unit, and as a result,may reduce the transparency of the transparent display panel.

The present disclosure provides an OLED display substrate, in which asub-pixel unit may be provided between transparent areas of thesub-pixel units of adjacent pixel units. This location may coincide withthe signal wires, but the sub-pixel unit is not covered with a blackmatrix. Since light is allowed to emit through the sub-pixel unit, theOLED display substrate according to the present disclosure thus makes itpossible to increase the brightness of a display panel incorporating thedisplay substrate.

FIG. 1 shows a schematic diagram of a top view of an OLED displaysubstrate according to an embodiment of the present disclosure.

As shown in FIG. 1, the OLED display substrate 10 comprises a first basesubstrate 101. A first electrode layer 102 is provided on the first basesubstrate 101, and a pixel define layer 108 is provided on the firstelectrode layer 102. Because FIG. 1 shows a top view of the OLED displaysubstrate, the component layers of the OLED display substrate 10 are notshown in FIG. 1. (corresponding to areas designated “opening” in FIG. 1)

The first base substrate 101 comprises a plurality of pixel units 101 aarranged in an array. At least one of the plurality of pixel units 101 acomprises a transparent area TA and at least two sub-pixel units(corresponding to areas designated 102 a in FIG. 1). The at least twosub-pixel units comprise at least one color sub-pixel unit and a whitesub-pixel unit. In some embodiments, at least one of the plurality ofpixel units 101 a comprises more than two sub-pixel units, and one ofthe sub-pixel units is a white sub-pixel unit and the other sub-pixelsare color sub-pixel units.

A first electrode layer 102 is provided on the first base substrate, andcomprises a plurality of first sub-electrodes 102 a. The firstsub-electrodes 102 a are block electrodes. Each of the plurality offirst sub-electrodes 102 a positionally corresponds to one of the atleast two sub-pixel units.

A pixel define layer 108 is provided on the first electrode layer 102,and comprises a plurality of openings. Each of the plurality of openingspositionally corresponds to a light-emitting region of one of the atleast two sub-pixel units and to the transparent area.

FIG. 2 shows a schematic diagram of a top view of an OLED displaysubstrate according to another embodiment of the present disclosure.

The first base substrate 101 comprises a plurality of pixel units 101 aarranged in an array. At least one of the plurality of pixel units 101 acomprising at least two sub-pixel units and a transparent area TA. Theat least two sub-pixel units comprise a first sub-pixel unit, the firstsub-pixel unit being arranged between the transparent areas TA ofadjacent pixel units in a first direction. In some embodiments, thesub-pixel units are configured to have a square shape or a rectangularshape. A width of each of the sub-pixel units may be in the range offrom about 70 μm to about 200 μm, and a length of the each of thesub-pixel units may be in the range of from about 200 μm to about 630μm. In some embodiments, the ratio of the length of a sub-pixel unit tothe width of the sub-pixel unit is in the range of from 1:1 to 9:1. Morepreferably, the length to width ratio of the sub-pixel unit other thanthe first sub-pixel unit is in the range of from 1.2:1 to 1:1. It isfurther understood that in some embodiments, the at least two sub-pixelunits have different dimensions from each other. In some embodiments,the pixel unit comprises more than two sub-pixel units, and at least aportion of the plurality of sub-pixel units have the same dimensions.

In some embodiments, the first sub-pixel unit is configured to have arectangular shape. For example, the width of the first sub-pixel unit isfrom about 70 μm to about 200 μm, and the length of the first sub-pixelunit is from about 200 μm to about 630 μm. In some embodiments, thefirst sub-pixel unit is configured to have a rectangular shape orientedso that the width direction of the rectangle is in the first direction,and the length direction of the rectangle is in the second direction,for example as shown in FIG. 1. In some embodiments, the ratio of thelength of the first sub-pixel unit to the width of the first sub-pixelunit is in the range of from 9:1 to 5:1. More preferably, the length towidth ratio of the first sub-pixel unit is 6:1. In some embodiments, thewidth of the first sub-pixel unit is about 70 μm, and the length of thefirst sub-pixel unit is about 420 μm.

In some embodiments, the width and length of the sub-pixel units otherthan the first sub-pixel unit may be in the range of from about 170 μmto about 200 μm. In some embodiments, at least one of the sub-pixelunits has a rectangular shape, and is dimensioned to have a width ofabout 170 μm and a length of about 200 μm. In some embodiments, at leastone of the sub-pixel units has a square shape, and is dimensioned tohave a width and a length of about 200 μm.

In some embodiments, the first sub-pixel unit is a white sub-pixel unit,that is, a sub-pixel unit configured to emit white light. A sub-pixelunit may be configured as a white sub-pixel unit according to anysuitable means known to a person of ordinary skill in the art. In someembodiments, the display substrate may be a white OLED (WOLED) displaysubstrate. In such embodiments, the light-emitting pattern in eachsub-pixel unit is composed of the same material, and is configured toemit white light. But, the display substrate further comprises a colorfilter layer that configures each sub-pixel unit to emit light of thedesired color. In other embodiments, the display substrate is a RGBWOLED display substrate, which does not include a color filter layer. Insuch embodiments, the light-emitting patterns in the sub-pixel units arecomposed of different materials, and are configured so that thesub-pixel units emit lights of different colors.

In some embodiments, the display substrate may comprise a red sub-pixelunit, a green sub-pixel unit, and a blue sub-pixel unit, and the firstsub-pixel unit is the white sub-pixel unit. The red, green, blue, andwhite sub-pixel units are arranged in this order in the first direction.In some embodiments, the sizes of the red, green, blue, and whitesub-pixel units, as measured by their surface areas (S_(red), S_(green),S_(blue), S_(white)) satisfy the following relationships:S_(blue)>S_(red)>S_(white), S_(blue)>S_(green)>S_(white). In someembodiments, S_(red)=S_(green).

As shown in FIG. 2, a first electrode layer 102 is provided on the firstbase substrate, and comprises a plurality of first sub-electrodes 102 a.The first sub-electrodes 102 a are block electrodes. Each of theplurality of first sub-electrodes 102 a positionally corresponds to oneof the at least two sub-pixel units.

A pixel define layer 108 is provided on the first electrode layer 102,and comprises a plurality of openings. Each of the plurality of openingspositionally corresponds to a light-emitting region of one of the atleast two sub-pixel units and to the transparent area.

The display substrate further comprises a plurality of pixel drivecircuits 105. Each of the plurality of pixel drive circuits 105 iselectrically coupled to a corresponding one of the plurality of firstsub-electrodes 102 a. Each of the plurality of pixel drive circuits 105is configured to supply a voltage to the corresponding firstsub-electrode 102 a, and drive the first sub-electrode 102 a to drive acorresponding light emitting pattern 103 a in the light-emitting layer103 (for example, as shown in FIG. 3) to emit light. The orthographicprojection of each pixel drive circuit 105 on the first base substrate101 at least partially overlaps with the orthographic projection of thecorresponding first sub-electrode 102 a on the first base substrate 101.In some embodiments, the orthographic projection of each pixel drivecircuit 105 on the first base substrate 101 is within the orthographicprojection of the corresponding first sub-electrode 102 a on the firstbase substrate 101. The configurations of the pixel drive circuits 105relative to the first sub-electrodes 102 a make it possible to avoidinterferences from the pixel drive circuits 105 on the light-emittingfunctions of the sub-pixel units.

As shown in FIG. 2, the orthographic projection of a pixel drive circuit105 electrically coupled to the first sub-electrode 102 a correspondingto the first sub-pixel unit on the first base substrate 101 partiallyoverlaps with an orthographic projection of a first sub-electrode 102 apositionally corresponding to another one of the at least two sub-pixelunits on the first base substrate 101. This overlap obviates the need tocover the first sub-pixel unit with a black matrix, so that light may beemitted through the light-emitting region of the first sub-pixel unit.The present disclosure thus increases the total surface area of thelight-emitting regions on the display substrate, making it possible toincrease the brightness of a transparent display panel.

In some embodiments, at least one of the plurality of pixel unitscomprises more than two sub-pixel units. For example, in the embodimentillustrated in FIG. 1, the display substrate comprises four sub-pixelunits. In such embodiments, the orthographic projection on the firstbase substrate of the pixel drive circuit 105 electrically coupled tothe first sub-electrode 102 a corresponding to the first sub-pixel unitpartially overlaps with an orthographic projection on the first basesubstrate of a first sub-electrode 102 a positionally corresponding tothe sub-pixel unit nearest to the first sub-pixel unit. In someembodiments, the sub-pixel unit nearest to the first sub-pixel unit is asub-pixel unit in the same pixel unit as the first sub-pixel unit. Inother embodiments, the nearest sub-pixel unit is a sub-pixel unit in apixel unit adjacent to the pixel unit to which the first sub-pixel unitbelongs. For example, in the embodiment illustrated in FIG. 1, the firstsub-pixel unit is between the transparent areas TA of adjacent pixelunits in the “x” direction. The orthographic projection on the firstbase substrate of the pixel drive circuit electrically coupled to thefirst sub-electrode may partially overlap with the orthographicprojection on the first base substrate of a first sub-electrodepositionally corresponding to the sub-pixel unit to the left of thefirst sub-pixel unit (i.e., in the same pixel unit as the firstsub-pixel unit) or to the right of the first sub-pixel unit (i.e., inthe adjacent pixel unit).

In some embodiments, the first sub-pixel unit is a white sub-pixel. Insuch embodiments, the orthographic projection on the first basesubstrate 101 of the pixel drive circuit 105 electrically coupled to thefirst sub-electrode 102 a corresponding to the white sub-pixel unitpartially overlaps with the orthographic projection on the first basesubstrate 101 of a first sub-electrode 102 a positionally correspondingto the sub-pixel unit nearest to the white sub-pixel unit.

Further as shown in FIG. 2, the display substrate comprises a pluralityof signal wires extending in a second direction. The second direction isoriented to intersect the first direction. As described above, the firstsub-pixel is arranged between the transparent areas TA of adjacent pixelunits in the first direction.

An orthographic projection of a light-emitting region of the firstsub-pixel unit on the first base substrate overlaps with an orthographicprojection of the plurality of signal wires on the first base substrate.In some embodiments, the orthographic projection of the light-emittingregion of the first sub-pixel unit on the first base substrate is withinthe orthographic projection of the plurality of signal wires on thefirst base substrate.

In the display substrate of the present disclosure, the first sub-pixelunit has no effect on the transparency of the OLED display substrate,and the transparency of the OLED display substrate is in the range offrom 30% to 45%. The present disclosure thus makes it possible toimprove the brightness of a display panel without modifying or alteringthe transparency of the display panel.

FIG. 3 shows a schematic diagram of a cross-sectional of an OLED displaysubstrate according to an embodiment of the present disclosure.

As shown in FIG. 3, the display substrate comprises the first basesubstrate 101 and the first electrode layer 102 on the first basesubstrate 101. The display substrate further comprises a light-emittinglayer 103 on the first electrode layer 102, and a second electrode layer104 on the light-emitting layer 103.

The first electrode layer 102 may comprise a plurality of firstsub-electrodes 102 a. Each of the plurality of first sub-electrodes 102a positionally corresponds to one of the at least two sub-pixel units.The light-emitting layer 103 may comprise a plurality of light-emittingpatterns 103 a. Each of the plurality of light-emitting patterns 103 apositionally corresponds to one of the at least two sub-pixel units.Each of the plurality of first sub-electrodes 102 a is electricallycoupled to a corresponding one of the plurality of light-emittingpatterns 103 a.

The second electrode layer 104 may be a continuous planar electrode, ormay be configured to comprise a plurality of block electrodes (forexample, in a similar manner as the first sub-electrodes 102 a of thefirst electrode layer). Each of the light emitting patterns 103 a iselectrically coupled to the second electrode layer 104. In someembodiments, the display substrate further comprises a first auxiliaryelectrode layer on the second electrode layer 104. The first auxiliaryelectrode layer is electrically coupled to the second electrode layer104.

The above descriptions illustrate the display substrate of the presentdisclosure primarily from the perspective of the first base substrate101. It is however understood that the structure and configuration ofthe display substrate of the present disclosure may also be describedfrom the perspective of the sub-pixel units. That is, for a givensub-pixel unit, the first sub-electrode 102 a corresponding in positionto that sub-pixel unit, the light-emitting pattern 103 a electricallycoupled to the first sub-electrode 102 a, and the second electrode layer104 on the light-emitting pattern 103 a, constitute the light emittingunit of that particular sub-pixel unit. In other words, each of thesub-pixel units in a pixel unit 101 a comprises a light-emitting unit,as described above, and a pixel drive circuit 105. The pixel drivecircuit 105 is electrically coupled to the sub-pixel unit's firstsub-electrode 102 a, and is configured to supply a voltage to the firstsub-electrode 102 a to drive the first sub-electrode 102 a to drive thelight emitting pattern 103 a to emit light.

In some embodiments, the display substrate further comprises a firstblack matrix on the second electrode layer 104. An orthographicprojection of the first black matrix on the first base substrate 101 iswithin an orthographic projection of the pixel define layer 108.

In some embodiments, the display substrate further comprises a firstcolor filter layer on a side of the first black matrix opposite from thefirst base substrate 101. The first color filter layer is arranged topositionally correspond to any one of the at least two sub-pixel otherthan the first sub-pixel unit and to the transparent area TA.

In at least some embodiments, the first electrode layer 102 comprises areflective electrode layer. Light emitted from the light emittingpatterns 103 a can be reflected by the first electrode layer 102, andemitted through the second electrode layer 104. The first electrodelayer 102 does not overlap with the transparent area TA. That is, thetransparent area TA is not covered by the first electrode layer 102.

FIG. 4 shows a circuit diagram for a pixel drive circuit according to anembodiment of the present disclosure.

The pixel drive circuit 105 comprises a capacitor 105 a, a first thinfilm transistor 105 b, and a second thin film transistor 105 c. Thepresent disclosure does not particularly limit the first thin filmtransistor 105 b and the second thin film transistor 105 c, which mayhave any appropriate construction and configuration known to a person ofordinary skill in the art depending on the specific implementation ofthe display substrate. For example, the first and second thin filmtransistors 105 b, 105 c may each comprise a gate electrode, a firstelectrode (either a source electrode, or a drain electrode), and asecond electrode (either a drain electrode if the first electrode is asource electrode, or a source electrode if the first electrode is adrain electrode). Further, it is understood that the pixel drive circuit105 according to the present disclosure may include any appropriateaccessories and/or components known to a person of ordinary skill in theart, for example, depending on the specific implementation of the pixeldrive circuit, without departing from the scope and spirit of thepresent disclosure.

The capacitor 105 a may comprise a first capacitor layer and a secondcapacitor layer. In some embodiments, a dielectric layer is providedbetween the first capacitor layer and the second capacitor layer. Thefirst capacitor layer is electrically coupled to the gate electrode ofthe first thin film transistor 105 b and the first electrode of thesecond thin film transistor 105 c. The second capacitor layer iselectrically coupled to the first electrode of the first thin filmtransistor 105 b and a corresponding one of the plurality of electrode102 a. The gate electrode of first thin film transistor 105 b iselectrically coupled to the first electrode of the second thin filmtransistor 105 c. In some embodiments, the second capacitor layer may beprovided in the same layer as the active layer of the first thin filmtransistor 105 b. That is, during fabrication, the second capacitorlayer and the active layer of the first thin film transistor 105 b maybe formed in the same patterning step.

Each pixel drive circuit 105 is electrically coupled to at least onesignal wire. The OLED display substrate according to the presentdisclosure may be provided with any appropriate signal wires known to aperson of ordinary skill in the art. For example, the OLED displaysubstrate may comprise a plurality of signal wires that include one ormore of earth lines, clock lines for transmitting clock signals, ADDlines for transmitting ADD signals (i.e., auxiliary data signals), VDDlines for transmitting VDD signals (i.e., digital power signals), VSSlines for transmitting VSS signals (i.e., digital ground signals), andthe like. In some embodiments, the gate electrode of the second thinfilm transistor 105 c may be electrically coupled to the output terminalof a gate scan line G1, for example, as shown in FIG. 4. The secondelectrode of the second thin film transistor 105 c may be electricallycoupled to the output terminal of a data input line D, for example, asshown in FIG. 4. The first electrode of the first thin film transistor105 b may be electrically coupled to the output terminal of a VDD line,for example, as shown in FIG. 4.

The first electrode layer 102 comprises a plurality of firstsub-electrodes 102 a. Each of the plurality of first sub-electrodes 102a corresponds in position to one of the sub-pixel units. Further, eachof the plurality of pixel drive circuits 105 is electrically coupled toone of the plurality of first sub-electrodes 102 a. The pixel drivecircuits 105 electrically coupled to the first sub-electrodes 102 a ofsub-pixel units other than the first sub-pixel unit are arranged topositionally correspond to the sub-pixel units themselves. In someembodiments, the display substrate comprises a first sub-pixel unit thatis configured to emit white light. This makes it possible to increasethe brightness of the display substrate. The location of the firstsub-pixel unit may coincide with the signal wires of the displaysubstrate. To prevent interferences from the signal wires, in thedisplay substrate of present disclosure, the pixel drive circuit 105electrically coupled to the first sub-electrode of the first sub-pixelunit is arranged partially in the sub-pixel unit nearest to the firstsub-pixel unit. More particularly, the orthographic projection on thefirst base substrate of the pixel drive circuit electrically coupled tothe first sub-electrode of the first sub-pixel partially overlaps withthe orthographic projection on the first base substrate of the firstsub-electrode of the nearest sub-pixel unit. In some embodiments, thepixel drive circuit 105 may therefore be provided outside the firstsub-pixel unit.

The display substrate further comprises a plurality of signal wiresextending in a second direction. The second direction is oriented tointersect the first direction. As described above, the first sub-pixelunit is arranged between the transparent areas TA of adjacent pixelunits in the first direction. An orthographic projection of alight-emitting region of the first sub-pixel unit on the first basesubstrate overlaps with an orthographic projection of the plurality ofsignal wires on the first base substrate. In some embodiments, theorthographic projection of the light-emitting region of the firstsub-pixel unit on the first base substrate is within the orthographicprojection of the plurality of signal wires on the first base substrate.In a pixel unit in a display substrate according to the presentdisclosure, the transparent area TA occupies about 40-60% of the surfacearea of the pixel unit, and each of the sub-pixel units is dimensionedto occupy substantially the same amount of the surface area of the pixelunit. The configurations of the display substrate of the presentdisclosure thus make it possible to significantly increase thebrightness of a display panel incorporating the display substrate.

FIG. 5 shows a schematic diagram of a top view of a pixel drive circuitof a sub-pixel unit of an OLED display substrate according to anembodiment of the present disclosure.

In the pixel drive circuit 105, the active layer of the first thin filmtransistor 105 b, the active layer of the second thin film transistor105 c, and the second capacitor layer 5 a 2 of the capacitor 105 a areprovided in the same layer, and may be collectively referred to as thefirst conductive pattern (shown with bold solid line in FIG. 5). Thepixel drive circuit 105 is also electrically coupled to certain signallines, including the gate scan line G1 and the VDD line. The gate scanline G1, the gate electrode of the first thin film transistor 105 b, andthe gate electrode of the second thin film transistor 105 c are providedin the same layer, and may be collectively referred to as the secondconductive pattern (shown with thin solid line in FIG. 5). The first andsecond electrodes of the first thin film transistor 105 b, the first andsecond electrodes of the second thin film transistor 105 c, and thefirst capacitor layer 5 a 1 of the capacitor 105 a are provided in thesame layer, and may be collectively referred as the third conductivepattern (shown with thin dotted line in FIG. 5).

The first capacitor layer 5 a 1 may be electrically coupled to the gateelectrode of the first thin film transistor 105 b via the first via holeV1. The first capacitor layer 5 a 1 may be electrically coupled to thefirst electrode of the second thin film transistor 105 c via the secondvia hole V2. The second capacitor layer 5 a 2 may be electricallycoupled to the first sub-electrode 102 a in the first sub-pixel unit viathe third via hole V3 (shown with bold dotted line in FIG. 5). Thefirst, second, and third via holes V1, V2, V3 are configured to connecttwo conductive patterns located in different layers. In someembodiments, the first, second, and third via holes V1, V2, V3 arelocated at the end of a conductive pattern. In some embodiments, thefirst, second, and third via holes V1, V2, V3 are configured as squareprisms, and the opening area of each of the via holes is 4 μm×4 μm, 6μm×6 μm, or 8 μm×8 μm.

The gate electrode of the first thin film transistor 105 b may beelectrically coupled to the first electrode of the second thin filmtransistor 105 c via the first capacitor layer 5 a 1.

The gate electrode of the second thin film transistor 105 c may beelectrically coupled to the gate scan line G1 via the coupling line 105d provided in the same layer as the first capacitor layer 5 a 1. Forexample, in some embodiments, one end of the coupling line 105 d may beelectrically coupled to the gate scan line G1 via the fourth via holeV4, and the other end of the coupling line 105 d may be electricallycoupled to the gate electrode of the second thin film transistor 105 cvia the fifth via hole V5. The fourth and fifth via holes V4, V5 may beconfigured similarly as the first, second, or third via holes V1, V2, V3described above.

The second electrode of the second thin film transistor 105 c may beprovided in the same layer as the data input line D. In someembodiments, the second electrode of the second thin film transistor 105c may be directly coupled to the data input line D.

The second electrode of the first thin film transistor 105 b may beelectrically coupled to the VDD line via the sixth via hole V6. Thesixth via hole V6 may be configured similarly as the first, second, orthird via holes V1, V2, V3 described above.

It is understood that the first capacitor layer 5 a 1 of the pixel drivecircuit 105 may be arranged and/or configured in any appropriate mannerknown to a person of ordinary skill in the art. The present disclosuredoes not particularly limit the arrangement or configuration of thefirst capacitor layer 5 a 1. Three illustrative, non-limitingembodiments are described below.

In some embodiments, for example, as shown in FIGS. 3 and 5, the firstcapacitor layer 5 a 1 may be provided in the same layer as the firstelectrode of the first thin film transistor 105 b.

In some embodiments, the first capacitor layer 5 a 1 may be provided inthe same layer as the first electrode layer 102.

In some embodiments, the first capacitor layer 5 a 1 may be configuredin the manner illustrated in FIG. 6. FIG. 6 shows a schematic diagram ofa cross-sectional of an OLED display substrate according to anotherembodiment of the present disclosure. As shown in FIG. 6, in someembodiments, the first electrode layer 102 may comprise a reflectiveelectrode layer 2 a 1 and a transparent electrode layer 2 a 2 arrangedin this order on the first base substrate 101. More particularly, thereflective electrode layer 2 a 1 and the transparent electrode layer 2 a2 are arranged in this order in a direction away from the first basesubstrate 101. Each of the plurality of first sub-electrodes 102 a ofthe first electrode layer 102 may comprise a reflective sub-electrode 2a 1 and a transparent sub-electrode 2 a 2.

In some embodiments, in each pixel drive circuit 105, the firstcapacitor layer 5 a 1 may be provided in the same layer as thetransparent electrode layer 2 a 2. In these embodiments, the firstcapacitor layer 5 a 1 is composed only of the material forming thetransparent electrode layer 2 a 2, and does not contain any of thematerial forming the reflective electrode layer 2 a 1. The secondcapacitor layer 5 a 2 provided in the same layer as the active layer ofthe first thin film transistor 105 b may also be composed of atransparent material. As such, when the first capacitor layer 5 a 1 iscomposed of a transparent material, the transparency of the resultingcapacitor 105 a in the pixel drive circuit 105 can increase thetransparency of the final OLED display substrate.

In some embodiments, in a pixel unit, the at least sub-pixel units maybe arranged in a row in the same direction as the length or longitudinaldirection of the transparent area TA, for example, as shown in FIG. 1(the length direction of the transparent area TA being designated as “x”in FIG. 1).

The at least two sub-pixel units may comprise a white sub-pixel unit. Insome embodiments, the length of longitudinal direction of the firstsub-pixel unit may be parallel to the width or transverse direction ofthe transparent area TA, for example, as shown in FIG. 1 (the widthdirection of the transparent area TA being designated as “y” in FIG. 1).

The sub-pixel units that are not the white sub-pixel unit may beselected from the group consisting of a red sub-pixel unit, a greensub-pixel unit, and a blue sub-pixel unit.

As shown in FIGS. 3 and 6, an OLED display substrate according to thepresent disclosure may further comprise a passivation layer 106, aflattening layer 107, and a pixel define layer 108 on the first basesubstrate 101. It is understood that the passivation layer, flatteninglayer, and pixel define layer may be configured and formed in anyappropriate manner known to a person of ordinary skill in the art dependon need, and the present disclosure is not particularly limited in theseregards.

As described above, in an OLED display substrate according to thepresent disclosure, one of the sub-pixel units in a pixel unit may belocated between transparent areas of sub-pixel units of adjacent pixelunits. This location may coincide with the signal wires on the displaysubstrate. In conventional technologies, the signal wires are usuallycovered with black matrix to prevent interferences between the signalwires and the pixel drive circuit coupled to the nearby sub-pixel unit.In contrast, in the present disclosure, the sub-pixel unit is notcovered with a black matrix. Since light is allowed to emit through thesub-pixel unit, the OLED display substrate according to the presentdisclosure thus makes it possible to increase the brightness of adisplay panel incorporating the display substrate.

The present disclosure also provides a display panel. FIG. 7 shows aschematic diagram of a display panel according to an embodiment of thepresent disclosure.

As shown in FIG. 7, the display panel may comprise a front plate 20 anda back plate. The back plate may comprise an OLED display substrateaccording to the present disclosure, for example, as shown in FIGS. 1,2, 3, and/or 6.

FIG. 8 shows a schematic diagram of a front plate for a display panelaccording to an embodiment of the present disclosure.

As shown in FIG. 8, the front plate may comprise a second base substrate201 and a second black matrix 202 on the second base substrate 201. Inthe assembled display panel, the orthographic projection of the secondblack matrix 202 on the first base substrate 101 does not overlap withthe orthographic projection of the first sub-pixel unit on the firstbase substrate 101.

In some embodiments, the orthographic projection of the second blackmatrix 202 on the first base substrate 101 overlaps with theorthographic projections of all portions of the OLED display substrateon the first base substrate 101 outside of the transparent area TA andthe sub-pixel units including the first sub-pixel unit. Put differently,the orthographic projection of the second black matrix 202 on the firstbase substrate 101 does not overlap with the orthographic projections onthe first base substrate 101 of the transparent area TA or the sub-pixelunits including the first sub-pixel unit.

In some embodiments, the front plate 202 may further comprise a secondcolor filter layer 203 on a side of the second black matrix 202 oppositefrom the second base substrate 201, for example, as shown in FIG. 8.

The second color filter layer is arranged to positionally correspond toany one of the at least two sub-pixel units other than the firstsub-pixel unit and to the transparent area. More particularly, thesecond color filter layer 203 may comprise a plurality of color filters203 a, each of the plurality color filters 203 a corresponding inposition to one of the sub-pixel units other than the first sub-pixelunit. In some embodiments, the second color filter layer 203 maycomprise a plurality of color filters 203 a selected from the groupconsisting of a red color filter, a green color filter, and a blue colorfilter.

In some embodiments, an insulation layer 204 and a second auxiliaryelectrode layer 205 are provided on a side of the second color filterlayer 203 opposite from the second base substrate 201, for example, asshown in FIG. 7. The second auxiliary electrode layer 205 is configuredto be electrically coupled to the second electrode layer 104 of the OLEDdisplay substrate in the back plate. The second auxiliary electrodelayer 205 may be composed of a metallic material. The second electrodelayer 104 is an electrode layer having transparency, and the secondelectrode layer 104 may be composed of any suitable transparent materialknown to a person of ordinary skill in the art, including indium tinoxide, indium-doped zinc oxide, and the like. The resistance of anelectrode layer having transparency tends to be larger, while theresistance of a metallic material tends to be smaller. By electricallycoupling the second auxiliary electrode layer 205 and the secondelectrode layer 104, the present disclosure makes it possible to reducethe resistance in the second electrode layer 104.

The present disclosure also provides a method of fabricating an OLEDdisplay substrate. The OLED display substrate may be as described above.

In some embodiments, for example, to form the OLED display substrateillustrated in FIG. 1, the method may comprise forming a first basesubstrate comprising a plurality of pixel units arranged in an array, atleast one of the plurality of pixel units comprising at least twosub-pixel units and a transparent area; forming a first electrode layeron the first base substrate, the first electrode layer comprising aplurality of first sub-electrodes, each of the plurality of firstsub-electrodes positionally corresponding to one of the at least twosub-pixel units; forming a pixel define layer on the first electrodelayer, the pixel define layer comprising a plurality of openings, eachof the plurality of openings positionally corresponding to alight-emitting region of one of the at least two sub-pixel units and tothe transparent area; and forming a plurality of pixel drive circuits,each of the plurality of pixel drive circuits being electrically coupledto a corresponding one of the plurality of first sub-electrodes. The atleast two sub-pixel units comprise a first sub-pixel unit, the firstsub-pixel unit being arranged between transparent areas of adjacentpixel units in a first direction. An orthographic projection of a pixeldrive circuit electrically coupled to the first sub-electrodecorresponding to the first sub-pixel unit on the first base substratepartially overlaps with an orthographic projection of a firstsub-electrode positionally corresponding to another one of the at leasttwo sub-pixel units on the first base substrate.

FIG. 9 shows a flow chart for a method of fabricating an OLED displaysubstrate according to an embodiment of the present disclosure. The OLEDdisplay substrate illustrated in FIGS. 2 and 3 may be fabricated asshown in FIG. 9.

In step 901, a plurality of pixel drive circuits are formed on the firstbase substrate.

Each of the plurality of pixel drive circuits comprises a capacitor, afirst thin film transistor, and a second thin film transistor. Thestructure and configuration of each pixel drive circuit may be asdescribed above, and the corresponding descriptions are not repeatedhere.

More particularly, a first conductive pattern forming film is formed onthe first base substrate by any suitable means known to a person ofordinary skill in the art, including, but not limited to, deposition,coating, sputtering, and the like. A single patterning step is thenperformed using a single mask on the first conductive pattern formingfilm to form the first conductive pattern.

The first conductive pattern may comprise the active layer of the firstthin film transistor, the active layer of the second thin filmtransistor, and the second capacitor layer of the capacitor.

A first gate insulation layer forming film and a second conductive layerforming film are formed in turn on the first base substrate, on whichthe first conductive pattern has been formed. The first gate insulationlayer forming film and the second conductive pattern forming film may beformed by any suitable means known to a person of ordinary skill in theart, including, but not limited to, deposition, coating, sputtering, andthe like. A single patterning step is then performed using a single maskon the first gate insulation layer forming film and the secondconductive pattern forming film to form the gate insulation layer andthe second conductive pattern, respectively.

The second conductive pattern may comprise the gate electrode of thefirst thin film transistor, and the gate electrode of the second thinfilm transistor. After forming the gate insulation layer and the secondconductive layer, the first conductive layer may be subject to treatmentthat imparts conductivity to portions of the first conductive layeroutside the orthographic projections of the gate electrodes of the firstand second thin film transistors on the first conductive pattern.

A dielectric layer forming film is formed on the first base substrate,on which the second conductive pattern has been formed. The dielectriclayer forming film may be formed by any suitable means known to a personof ordinary skill in the art, including, but not limited to, deposition,coating, sputtering, and the like. A single patterning step is thenperformed using a single mask on the dielectric layer forming film toform the dielectric layer.

A third conductive pattern forming film is formed on the first basesubstrate, on which the dielectric layer has been formed. The thirdconductive pattern forming film may be formed by any suitable meansknown to a person of ordinary skill in the art, including, but notlimited to, deposition, coating, sputtering, and the like. A singlepatterning step is then performed using a single mask on the thirdconductive pattern forming film to form the third conductive layer. Thethird conductive pattern may comprise the first and second electrodes ofthe first thin film transistor, the first and second electrodes of thesecond thin film transistor, and the first capacitor layer.

It is understood that even though the above descriptions relate to a topgate-type first and second thin film transistors, the first and secondthin film transistors may also be bottom gate-type.

Each of the patterning steps described above may be any suitablepatterning process known to a person of ordinary skill in the art, andis not particularly limited. For example, the first patterning step maycomprise photoresist coating, exposure, development, etching, andphotoresist stripping.

In step 902, a passivation layer and a flattening layer are formed onthe first base substrate, on which the plurality of pixel drive circuitshave been formed.

The passivation layer may be composed of any suitable material known toa person of ordinary skill in the art, including, but not limited to,silicon dioxide (SiO₂), silicon nitride (Si₃N₄), silicon-oxy-nitride(SiO_(x)N_(y)), and the like.

The flattening layer may be composed of any suitable material known to aperson of ordinary skill in the art, including, but not limited to,acrylic resin, epoxy, and the like.

More particularly, a passivation layer forming film and a flatteninglayer forming film may be formed on the first base substrate by anysuitable means known to a person of ordinary skill in the art,including, but not limited to, deposition, coating, sputtering, and thelike. A single patterning step is then performed using a single mask onthe passivation layer forming film and the flattening layer forming filmto form the passivation layer and the flattening layer, respectively.The patterning step may be any suitable patterning process known to aperson of ordinary skill in the art, and is not particularly limited.For example, the first patterning step may comprise photoresist coating,exposure, development, etching, and photoresist stripping.

In step 903, the first electrode layer, the pixel define layer, thelight-emitting layer, and the second electrode layer are formed on thefirst base substrate, on which the flattening layer has been formed.

A first electrode layer forming film is formed on the first basesubstrate by any suitable means known to a person of ordinary skill inthe art, including, but not limited to, deposition, coating, sputtering,and the like. The first electrode layer forming film comprises areflective electrode layer and a transparent electrode layer arranged ina stack. The reflective electrode layer may be composed of a metallicmaterial, which may be any suitable metallic material known to a personof ordinary skill in the art. For example, the reflective electrodelayer may be composed of Ag, Cu, Al, Mo, and the like. In someembodiments, the reflective electrode layer may comprise a plurality ofmetal layers, for example, MoNb/Cu/MoNb and the like. In someembodiments, the reflective electrode layer may be composed of an alloy,including AlNd, MoNb, and the like. The transparent electrode layer maybe composed of any suitable transparent material known to a person ofordinary skill in the art, including, but not limited to, indium tinoxide (ITO).

A single patterning step is then performed using a single mask on thefirst electrode layer forming film to form the first electrode layer.The first electrode layer comprises a plurality of first sub-electrodes.

A pixel define layer forming film is formed on the first base substrateby any suitable means known to a person of ordinary skill in the art,including, but not limited to, deposition, coating, sputtering, and thelike. The pixel define layer may be composed of an organic material,including polyimide, poly(methyl methacrylate) (PMMA),polydimethylsiloxane, and the like.

A single patterning step is then performed using a single mask on thepixel define layer forming film to form the pixel define layer.

The light-emitting layer is formed on the first base substrate, on whichthe pixel define layer has been formed, by an inkjet printing process.

The second electrode layer is formed on the first base substrate, onwhich the light-emitting layer has been formed, by any suitable meansknown to a person of ordinary skill in the art, including, but notlimited to, deposition, coating, sputtering, and the like. The secondelectrode layer may be composed of materials such as indium zinc oxideand the like. In some embodiments, the second electrode layer is acontinuous layer.

Each of the patterning steps described above may be any suitablepatterning process known to a person of ordinary skill in the art, andis not particularly limited. For example, the first patterning step maycomprise photoresist coating, exposure, development, etching, andphotoresist stripping.

Steps 901 to 903 may be performed to obtain the OLED display substrateillustrated in FIG. 3. To form the OLED display substrate illustrated inFIG. 6, it is not necessary to form the first capacitor layer whenforming the third conductive pattern in step 901. Instead, the firstcapacitor layer is formed in step 903 when forming the first electrodelayer. More particularly, two patterning steps are performed to form thefirst electrode layer and the first capacitor layer. Performing twopatterning steps allows the first capacitor layer to be formed ofmaterials such as indium tin oxide, which can ensure the transparency ofthe capacitor in the pixel drive circuit.

A person of ordinary skill in the art would readily appreciate that theprinciples and embodiments of the OLED display substrate described aboveapply to the OLED display substrate fabricated according to the presentdisclosure. For convenience and clarity, the details of the OLED displaysubstrate of the present disclosure are not repeated here.

In an OLED display substrate according to the present disclosure, one ofthe sub-pixel units in a pixel unit may be located between transparentareas of sub-pixel units of adjacent pixel units. This location maycoincide with the signal wires on the display substrate. In conventionaltechnologies, the signal wires are usually covered with black matrix andthe pixel drive circuit coupled to the nearby sub-pixel unit. Incontrast, in the present disclosure light is allowed to emit through thesub-pixel unit arranged on the signal wires, the OLED display substrateaccording to the present disclosure thus makes it possible to increasethe brightness of a display panel incorporating the display substrate.

The present disclosure also provides a display device. The displaydevice may comprise a display panel as described above. A display panelaccording to the present disclosure may be integrated into any deviceconfigured to provide a display function, including, but not limited to,an electronic paper, a mobile phone, a tablet, a television, a computer,a display, a notebook computer, a digital photo frame, a navigationsystem, and any other products or components that provide a displayfunction.

When required to exhibit the same or similar level of brightness as aconventional transparent display device, the display device according tothe present disclosure is able to achieve that brightness without havingto supply a higher voltage to the light-emitting layer in the displaydevice. This is because the brightness of the display device accordingto the present disclosure is already higher than is possible withconventional display devices. As such, the light-emitting layer of thedisplay device according to the present disclosure can enjoy a longerlifespan, which can in turn increase the useful life of the displaydevice.

Further, since the display device according to the present disclosuremay incorporate white sub-pixel units, it is necessary to activate onlythe white sub-pixel units in order to produce black-and-white displays.It is not necessary to activate other color sub-pixel units for ablack-and-white display. This makes it possible to reduce the displaydevice's power consumption.

References in the present disclosure made to the term “some embodiment,”“some embodiments,” and “exemplary embodiments,” “example,” and“specific example,” or “some examples” and the like are intended torefer that specific features and structures, materials orcharacteristics described in connection with the embodiment or examplethat are included in at least some embodiments or example of the presentdisclosure. The schematic expression of the terms does not necessarilyrefer to the same embodiment or example. Moreover, the specificfeatures, structures, materials or characteristics described may beincluded in any suitable manner in any one or more embodiments orexamples. In addition, for a person of ordinary skill in the art, thedisclosure relates to the scope of the present disclosure, and thetechnical scheme is not limited to the specific combination of thetechnical features, and also should cover other technical schemes whichare formed by combining the technical features or the equivalentfeatures of the technical features without departing from the inventiveconcept. Unless otherwise defined, all the technical and scientificterms used herein have the same meanings as commonly understood by oneof ordinary skill in the art to which the present invention belongs.Terms such as “first,” “second,” and so on, are not intended to indicateany sequence, amount or importance, but distinguish various components.Terms such as “comprises,” “comprising,” “includes,” “including,” and soon, are intended to specify that the elements or the objects statedbefore these terms encompass the elements or the objects and equivalentsthereof listed after these terms, but do not preclude the other elementsor objects. Phrases such as “connect”, “connected”, and the like, arenot intended to define a physical connection or mechanical connection,but may include an electrical connection, directly or indirectly. Termssuch as “on,” “under,” “right,” “left” and the like are only used toindicate relative position relationship, and when the position of theobject which is described is changed, the relative position relationshipmay be changed accordingly.

The principle and the embodiment of the present disclosures are setforth in the specification. The description of the embodiments of thepresent disclosure is only used to help understand the embodiments ofthe present disclosure and the core idea thereof. Meanwhile, for aperson of ordinary skill in the art, the disclosure relates to the scopeof the disclosure, and the technical scheme is not limited to thespecific combination of the technical features, and also should coveredother technical schemes which are formed by combining the technicalfeatures or the equivalent features of the technical features withoutdeparting from the inventive concept. For example, technical scheme maybe obtained by replacing the features described above as disclosed inthis disclosure (but not limited to) with similar features.

What is claimed is:
 1. A display substrate, comprising: a first basesubstrate comprising a plurality of pixel units arranged in an array,wherein each of the plurality of pixel units includes a transparentarea, a white sub-pixel unit, at least two color sub-pixel units, and aplurality of signal wires; a first electrode layer, a second electrodelayer, and a light-emitting layer on the first base substrate, whereinthe first electrode layer includes a plurality of first sub-electrodesdisposed in the white sub-pixel unit and each of the color sub-pixelunits; and a plurality of pixel drive circuits, wherein each of theplurality of pixel drive circuits is electrically coupled to acorresponding one of the plurality of first sub-electrodes; wherein anorthographic projection of the white sub-pixel unit on the first basesubstrate partially overlaps with an orthographic projection of theplurality of signal wires on the first base substrate; an orthographicprojection of a pixel drive circuit corresponding to a firstsub-electrode of the white sub-pixel unit on the first base substrate islocated between an orthographic projection of the transparent area onthe first base substrate and an orthographic projection of a targetfirst sub-electrode on the first base substrate, and the target firstsub-electrode is electrically coupled to one of the at least two colorsub-pixel units adjacent to the white sub-pixel unit in one of theplurality of pixel units.
 2. The display substrate according to claim 1,wherein the orthographic projection of the white sub-pixel unit on thefirst base substrate is located inside the orthographic projection ofthe plurality of signal wires on the first base substrate.
 3. Thedisplay substrate according to claim 1, wherein each of the plurality ofpixel drive circuits comprises a capacitor, a first thin filmtransistor, and a second thin film transistor, the capacitor comprises afirst capacitor layer and a second capacitor layer, the first thin filmtransistor comprises a first active layer, a first gate electrode, afirst source electrode, and a first drain electrode, the second thinfilm transistor comprises a second active layer, a second gateelectrode, a second source electrode, and a second drain electrode, thefirst capacitor layer is electrically coupled to the first gateelectrode, and one of the second source electrode and the second drainelectrode, the second capacitor layer is electrically coupled to one ofthe first source electrode and the first drain electrode, and one of theplurality of electrode corresponding to the pixel drive circuit, and thesecond capacitor layer and the first active layer is disposed in a samelayer.
 4. The display substrate according to claim 3, wherein the firstelectrode layer comprises a reflective electrode layer and a transparentelectrode layer arranged in this order in a direction away from thefirst base substrate.
 5. The display substrate according to claim 3,wherein the first capacitor layer and one of the first source electrodeand the first drain electrode is disposed in a same layer.
 6. Thedisplay substrate according to claim 1, wherein the at least two colorsub-pixel units includes a red sub-pixel unit, a green sub-pixel unit,and a blue sub-pixel unit.
 7. A display panel, comprising: a front plateand a back plate facing each other; wherein the back plate includes thedisplay substrate of claim 1; the front plate include a second basesubstrate and a black matrix, the black matrix is disposed on the secondbase substrate, and an orthographic projection of the black matrix onthe first base substrate does not overlap with the orthographicprojection of the white sub-pixel unit on the first base substrate. 8.The display panel according to claim 7, wherein the front plate furtherincludes a color filter layer, and the color filter layer include aplurality of color filters, each of the plurality of color filters isarranged to positionally correspond to one of the at least two colorsub-pixel units.
 9. The display panel according to claim 7, wherein thedisplay substrate further includes the light-emitting layer on the firstelectrode layer, and a second electrode layer on the light-emittinglayer.
 10. The display panel according to claim 7, wherein a pixeldefine layer is disposed on the first electrode layer, the pixel definelayer comprising a plurality of openings, each of the plurality ofopenings positionally corresponding to a light-emitting region of one ofthe at least two color sub-pixel units and the white sub-pixel unit andto the transparent area.
 11. The display panel according to claim 8,wherein the display substrate further includes the black matrix isdisposed on the second electrode layer, and an orthographic projectionof the black matrix on the first base substrate is within anorthographic projection of the pixel define layer.
 12. The display panelaccording to claim 7, wherein the first electrode layer comprises areflective electrode layer and a transparent electrode layer arranged inthis order in a direction away from the first base substrate.
 13. Thedisplay panel according to claim 7, wherein each of the plurality ofpixel drive circuits comprises a capacitor, a first thin filmtransistor, and a second thin film transistor, the capacitor comprises afirst capacitor layer and a second capacitor layer, the first thin filmtransistor comprises a first active layer, a first gate electrode, afirst source electrode, and a first drain electrode, the second thinfilm transistor comprises a second active layer, a second gateelectrode, a second source electrode, and a second drain electrode, thefirst capacitor layer is electrically coupled to the first gateelectrode, and one of the second source electrode and the second drainelectrode, the second capacitor layer is electrically coupled to one ofthe first source electrode and the first drain electrode, and one of theplurality of electrode corresponding to the pixel drive circuit, and thesecond capacitor layer and the first active layer is disposed in a samelayer.
 14. The display panel according to claim 13, wherein the firstcapacitor layer is provided in a same layer as one of the first sourceelectrode and the first drain electrode.
 15. A display device,comprising: a display substrate according to claim 1, and an oppositesubstrate comprising a second base substrate and a second black matrixon the second base substrate, wherein an orthographic projection of thesecond black matrix on the first base substrate is within anorthographic projection of the pixel define layer on the first basesubstrate.
 16. The display device according to claim 15, furthercomprising a second color filter layer on a side of the second blackmatrix opposite from the second base substrate, wherein the second colorfilter layer is arranged to positionally correspond to any one of the atleast two sub-pixel units other than the first sub-pixel unit and to thetransparent area.